This invention relates to emulsions of polymeric materials. In another aspect, this invention relates to novel optically clear stable emulsions formed with ethylene homopolymers and/or copolymers. In still another aspect, this invention relates to novel, optically clear liquid polish formulations which contain emulsions of ethylene polymers.
Various polymeric emulsions are known in the art which are used as polishes, coatings and other similar surface treating compositions. Emulsions of oxidized polyethylene have been widely used in such polish formulations. The oxidized polyethylenes were produced by telomerization of ethylene and subsequent oxidation of the telomer, or by thermal degradation of high molecular weight polyethylenes to low molecular weight products which are then oxidized as disclosed in U.S. Pat. No. 2,964,487 and 2,928,797. The hydrophilic oxygenated groups on the resulting oxidized polymeric particles allow the particles to be emulsified. Such emulsions rarely have a molecular weight more than about 3000. However, the oxygenated polyethylene materials have a disagreeable odor which taints the emulsions prepared therefrom and the products which contain such emulsions. Furthermore, these emulsions typically have a yellow tinge.
Improved stable polyethylene emulsions which have found satisfactory use in coatings, lacquers, paints and polishes and which do not have the inherent disagreeable odor or color of the oxidized polyethylenes, have been produced by emulsion polymerization techniques such as set forth in U.S. Pat. Nos. 3,226,352, 3,244,652 and 3,352,807. These emulsions polymerized polyethylenes have molecular weights ranging from about 7000 to about 40,000 and particle sizes ranging broadly from about 200 angstroms to about 5,000 angstrom units with the average particle size of the particles being 500 angstrom units or more. However, these emulsion polymerized polyethylenes generally have a milky translucent color. Perhaps the clearest of such emulsions are produced by the process set forth in U.S. Pat. No. 3,352,807 and are disclosed to have a light transmission of from about 40% to about 90% (on a sample diluted to 0.06% solids) and as determined by a conventional Bausch & Lomb "Spectronic 20" spectrophotometer using distilled water as the 100% transmission calibration standard and utilizing a wave length of 400 millimicrons. However, even these emulsions contain a milky tint or hue and cannot be satisfactorily combined with normally water clear coating compositions without forming a translucent coating or polish composition.